Reusable pressurized dispensing device



Dec. 24, 1968 c. 1.. SANDS 3,417,901

REUSABLE PRESSURIZED DISPENSING DEVICE Filed July 6, 1967 2 Sheets-Sheet1 fig 1 fiQ- si f I8 17 lb 12 mvzwroz Queue .4. 64/1/05 av W /MM MI, 5Kim ATTORNEYS 1968 c. L. SANDS REUSABLE PRESSURIZED DISPENSING DEVICE 2Sheets-Sheet 2 Filed July 6, 1967 INVENTOR Cx/Aezzs Z. SANDS aY mM/Mm,flaw, zjapiqo, 5 mm ATTORNEYS United States Patent 3,417,901 REUSABLEPRESSURIZED DISPENSING DEVICE Charles L. Sands, 901 Mayfair, Champaign,Ill. 61820 Filed July 6, 1967, Ser. No. 651,593 6 Claims. (Cl. 222-95)ABSTRACT OF THE DISCLOSURE Disclosed is a reusable pressurizeddispensing device which has a sealed chamber to hold a propellant whichcan be liquified in a home referigerator, and which will boil belowoperating temperatures in order to force the liquid to be dispensed fromthe dispensing device. The device may be refilled by cooling to liquefythe propellant and opening the device to add more material to bedispensed.

This invention relates to a pressurized can suitable for dispensingfluid products, whereby the can can be reused without the necessity ofit being repressurized.

The dispensing of many substances such as shaving cream, deodorants,paint, insecticides and the like directly from packages in which theyare stored and transported under pressure, and from which they areeventually used, has grown to be an important segment of industry. Theeffectiveness of the aerosol bomb as a means for dispensing certainliquids, such as insecticides, is well known. The mechanism by whichthese liquids are generally dispensed, according to the prior art, hasbeen determined to a large extent by the compatability of the liquid tobe dispensed and the propellant. The principal mechanism by which theseaerosol bombs operate is to mix insecticide or the like with a liquidpropellant having a sufiiciently low boiling point to provide themixture with a vapor pressure sufficiently high to cause the liquid tobe ejected forceably from the container when the dispensing valve isopen. Low boiling liquids such as the chlorofluoro methanes, methylchloride, methylene chloride, methyl bromide and others have been usedin these applications. In such applications the low boiling liquidpropellant is generally a component of the product which is dispensedand the propellant is irrecoverably dispersed in the air.

A second type of aerosol bomb contains a propellant and a liquid to bedispensed which are not miscible. In such aerosol bombs, by usingappropriate valving systems, the propellant merely maintains a pressurewithin the bomb and the liquid to be dispensed is forced out of the bombby the pressure created by the propellant. In such cases, it is requiredthat the liquid to be dispensed and the propellant be compatible atleast to the extent that they cause no chemical reaction, excess heat,corrosion or the like, even though it is necessary that they beimmiscible with one another. Such bombs are handicapped by therequirement that they be operated in a particular attitude in order toavoid discharging the propellant before all of the liquid to bedispensed is exhausted. Even when operated in the chosen attitude,usually at the conclusion of the discharge of the liquid, the propellantis discharged into the air.

In both these types of prior art dispensers, care must be taken inselecting the propellant in order that it has the correct miscibility,or irnmiscibility as the case requires, as well as the lack of corrosionor chemical reaction and general compatibility with the liquid to bedispersed. Additionally, certain propellants, such as some of thehydrocarbons, are highly inflammable and not suitable for use in someapplications.

The present invention overcomes the foregoing problems by providing areusable pressurized package or container which contains a propellant ina completely closed chamber and a separate area or chamber for theliquid to be dispensed from the package. The liquid to be dispensed issubjected to pressure from the propellant and the liquid may be pushedfrom the package or container by this pressure through a suitable valvemeans. Further, the present invention is based on the discovery that apractical reusable aerosol package can be made by selecting a propellantwhich is gaseous at the operating temperature (the temperature at whichit is desired to dispense the liquid from the device) but which may beliquified by cooling to a readily achievable temperature, e.g. thetemperatures achieved by a household refrigerator freezer section.

Since the propellant is incapsulated by a completely closed chamber,problems such as reactivity between the propellant and the liquid to bedispensed, and loss of propellant during or after the dispensing of theliquid to be dispensed are obviated. Thus, this invention permits thereuse of the propellant supply. This is accomplished by placing thecomplete device or the propellant chamber alone in a refrigerated area,having temperature sufliciently low to liquify the propellant, and thuscollapse the propellant chamber. Following this, the balance of thedevice is filled with liquid to be dispensed and the device is closed.The device is then permitted to warm up sufficiently to vaporize atleast part of the propellant which in turn causes a pressure to beapplied to the liquid to be dispensed. Thereafter when the valve systemis actuated, the liquid to be dispensed, is dispensed under the pressureexerted by the vaporizing propellant.

The invention may be better understood by reference to the accompanyingdrawings wherein, in the interest of clarity, certain figures have beenshown on a somewhat exaggerated scale and wherein:

FIGURE 1 is a side elevational view, taken in section, of the firstembodiment showing a propellant chamber which is separate from thecontainer, a liquid chamber which is also separate from the container,and a container having a valve opening.

FIGURE 2 is a similar elevational view, of a section of the secondembodiment wherein the propellant chamber is separate from thecontainer, but the liquid to be dispensed is merely held in thecontainer.

FIGURE 3 is an elevational view taken in section of an embodiment of theinvention Where the propellant chamber, while separated from the liquidchamber, is an integral part of the container. This figure also shows afilling opening.

FIGURE 4 is a side elevational view of a modification of the embodimentshown in FIGURE 1 wherein the bag holding the liquid to be dispensed ispermanently mounted to the collar of the container and whereby .thevalve mechanism may be withdrawn to fill or refill the liquid bag.

FIGURE 1 shows a container 11 which may be made of metal or glass or anyother convenient material. The container comprises a top member 12 and abottom member 13 which are secured together in such a way that pressurein the container will not disengage the top from the bottom. Thefastening means may be a threading arrangement as shown at 9, or asimple bayonet lock wherein the top portion 12 extends around the upperperiphery of the bottom portion 13, and can be locked merely by rotatingthe upper portion with respect to the bottom portion for severaldegrees. It will be obvious to those skilled in the art that manyvariations may be made to the means for keeping the container closed.

The upper portion of the container is fitted with a suitable valvingmeans 14 (not shown in detail) and a locking system 16 for securing thebag containing the liquid product to be dispensed to the upper portionof the container. Again, this may be done in any convenient way.

It has been found satisfactory that an annular projection from the lowerend of the valve body 17 may be fitted with an annular detent 18 and aring 19 which may be used to clamp the bag containing the liquid to bedispensed 20 to the valve means. This structure is more clearly seen byreference to FIGURE 4.

It is preferred, though it is not absolutely necessary, a guard cage 22extending below the valving means, and attached thereto, to preventeither the liquid containing bag 20 or the propellant containing bag 26from collapsing across the throat of the valving means. This guard cagemay be made in any convenient form and may be raised to extend aconsiderable distance into the container 11, as illustrated by FIGURE 2.

Many alternative sealing means for sealing the liquid bag 20 to thevalve means 14 will occur to those skilled in the art, and thisinvention contemplates such other methods of sealing. Another methodwhich might be commercially adaptable is to permanently heat seal a maleor female threaded member to the bag 20 which threads would match upwith threads placed on the valving means on the annular projection 17,whereby the bag could be screwed onto the valving means 14. Such anadaptation would be usually on a bag that was a throwaway or arefillable bag. This invention contemplates the bag 20 being permanentlysealed to the lower portion of the valve means 17, where the valvemeans, as shown in FIGURE 4, is removable to permit refilling the bag 20with liquid to be dispensed.

The container 11 also houses a propellant bag 26 which may be made ofany convenient material. It is essential that the propellant bag be madeof some material that is fairly impermeable to the propellant used, anda material which is compatible, i.e. will not react or corrode when incontact with the propellant 28. It is necessary that the propellant bagbe able to expand to approximately fill the container 11. This inventioncontemplates two principal modes by which this may be accomplished.First, the bag may be made of a nonresilient, but flexible material,such as polyethylene or the like, of a size such to approximately fillthe container 11. When the propellant in the propellant bag 26 iscollapsed, the bag will collapse to a crumpled, wrinkled form, leavingmost of the container 11 unfilled. The second mode contemplates apropellant bag made of a rubbery, resilient, or stretchable materialsuch as natural or synthetic rubber whereby the physical dimensions maybe altered, i.e. shrink or expand, according to the pressure exerted bythe propellant which in turn is proportional to the temperature of thepropellant.

It is preferred that when the propellant bag is made of stretchablematerial, that a means be employed to limit its uppermost size, in orderto permit easy handling while it is in its warm or completely expandedstate. It has been found, that this can be accomplished by housing thepropellant bag within a fish net or a mesh stocking whereby theexpansion of the propellant bag is limited to something close toapproximately the volume of the container 11.

FIGURE 2 illustrates a second embodiment wherein the material to bedispensed occupies that portion of the container not occupied by thepropellant chamber. Although this is not the preferred embodiment, itmay be useful for some applications. The container used in thisembodiment must be essentially watertight in order to prevent leakage ofthe material to be dispensed. In this connection, a threaded connectionbetween the top 12 and bottom 13 of the container is preferred. Suitablegaskets and the like (not illustrated) may be used if desired.

FIGURE 3 illustrates a further embodiment, wherein the propellantchamber is formed in part by the lower portion of the container. As inFIGURE 2, the liquid to be dispensed occupies that portion of thecontainer not occupied by the propellant chamber, and thus, thecontainer must be fluid tight. Also, shown is a filling open- 4 ing 6,which may be used to refill the device. Such a filling opening also maybe used in connection with the embodiment shown in FIG. 2.

The material from which the propellant chamber is manufactured may varyover wide limits, but may be divided into two general categories, asmentioned above. Although the drawings attached hereto have shown thepropellant chamber 26 to be unwrinkled in nature, indieating anextensible flexible material, the invention is not so limited. Suitablematerials from which the propellant chamber may be made include thevarious synthetic rubbers such as butyl rubber, polybutadiene, ABSpolymers, styrene-butadiene rubbers, the various acrylonitrile rubbersand natural rubbers. Among the relatively nonextensible but flexiblematerials which may be used are vinyl chloride, polyethylene,polypropylene nylons, and similar materials.

In the first embodiment, as illustrated by FIGURE 1, the chamber whichcontains a liquid to be dispensed, may likewise be made out of either aflexible extensible material or an inextensible flexible material.Generally, the same materials which are used for the propellant bag aresuitable for use as the chamber for the liquid to be dis pensed,provided the materials are non-reactive with the liquid to be dispensed.

In the practice of this invention it is necessary to select a propellantwhich has a boiling point below the temperature at which the reusablepressurized package is to be used. It is necessary, for practicaloperation, that the boiling point of the propellant not be too low, inorder that the propellant may be liquified conveniently when it isnecessary to recharge the reusable package. Generally, the boiling pointof the propellant should be higher than 20 and preferably between 0 F.and 60 F.

It has been found that dichlorotetrafluoro ethane, sold under thetrademark Freon 114 is particularly suitable for use as a propellant inthe dispensing devices of this invention. The dichlorotetrafluoro ethanehas a boiling point of 38.4 F. with a latent heat of vaporization at oneatmosphere of 58.3 B.t.u.s per pound (which is relatively low). Othermaterials which may be used as propellants in my invention include ethylchloride, methyl chloride, sulfur dioxide, Freon 21(dichlorofluoromethane) and others.

It is essential that the propellant chamber be completely closed, atleast during the operation of the pressurized package. Optionally, thepropellant chamber may be fitted with a valve system whereby thepropellant may be replenished to make up any loss because of diffusion.

Although the drawings show a particular valve means 14, the presentinvention is not limited thereto, but contemplates the use of a widevariety of valve systems which will be apparent to those skilled in theart. The valve means must have an external control means by which thevalve may be operated, and it must be able to remain closed under theapplication of the relatively low pressures generated by the propellant.Any valve means meeting these standards may be used in conjunction withthe present invention. The valve means may be mounted in any convenientmanner. As shown in FIGURE 4, it may be removable in part in order topermit the filling of the device with the material to be dispensed.

A dispensing package when constructed in a manner corresponding to thefirst embodiment of this invention has many advantages, and provides forflexible operation. The container can be used to dispense differentliquids simply by changing the liquid containing bag 20. Since thepropellant is completely separated from liquid to be dispensed, there isno dilution or adulteration of the product in the liquid containing bagand 100 percent pure product is dispensed. Should the propellant chamberfor some reason become punctured or otherwise unusuable, it

may be removed and a new chilled propellant bag be inserted at any time.Further, the throw-away bags may be used as a package for marketing theliquid to be dispensed.

Additionally, the liquid dispensing devices of this invention may beused to dispense semi-liquid or plastic materials such as catsup,molasses, putty and cement or glue in addition to liquid products. It isalso possible to dispense highly volatile products such as perfumes andsolvents from such a dispensing device.

The container 12 need not be in the shape of a can as shown in thedrawings, but may be in any form desired, including various decorativeforms. Since the device of this invention is reusable, it is designed tocompete with less expensive throw-away cans. Hence, the construction anddesign may be more expensive in nature than the throw-away dispensersand still achieve economic competition. While several embodiments ofthis invention have been shown and described, various adaptations andmodifications thereof may be made without departing from the scope ofthe appended claims:

I claim:

1. A reusable pressurized dispensing device which comprises a container;a permanently closed collapsible propellant chamber Within saidcontainer, said propellant chamber being adapted to approximately fillthe inner volume of said container, said propellant chamber containing21 propellant having a boiling point at atmospheric pressure above 20 F.and below the operating temperature of said device; said container beingsufliciently strong to contain said propellant when at operatingpressure, including a space adapted to hold material to be dispensed;readily removable and replaceable closure means for said container topermit insertion, at atmospheric pressure, of

said material to be dispensed, into said container when said propellantis at a temperature below its boiling point at atmospheric pressure;said container having a valve means in fluid communication with saidmaterial to be dispensed and the outside of said container; whereby theexpansion of said propellant tends to exert pressure on said material tobe dispensed in a manner tending to force it out of said containerthrough said valve means.

2. A device as described in claim 1, which includes a separate chamberfor the material to be dispensed said chamber being in fluid contactwith said valve means.

3. A device as described in claim 2, wherein the chamber for thematerial to be dispensed is removable from said container and detachablefrom said valve means.

4. A device as described in claim 2, wherein said closure includes saidvalve means.

5. A device as described in claim 1, wherein the propellant has aboiling point of between 0 F. and F.

6. A device as described in claim 2, wherein the propellant has aboiling point of between 0 F. and 60 F.

References Cited UNITED STATES PATENTS 2,689,768 9/1954 Falligant222386.5 2,815,152 12/1957 Mills 222-3865 2,823,953 2/1958 McGeorge222-386.5 2,978,144 4/ 1961 Rilinger et a1 222- 3,178,062 4/1965 Weltyet a1. 22295 3,184,113 5/1965 Curtis 222386.5 3,245,435 4/1966 Healy141-3 ROBERT B. REEVES, Primary Examiner.

H. S. LANE, Assistant Examiner.

U.S. Cl. X.R. l4l3; 222--386.5

